Doped, pyrogenically prepared oxides
AssigneeDegussa AG
InventorsHelmut Mangold, Rainer Golchert, Stipan Katusic, Karlheinz Janzon
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Abstract
Doped, pyrogenically prepared oxides of metals and/or non-metals which are doped with one or more doping components in an amount of 0.00001 to 20 wt. %. The doping component may be a metal and/or non-metal or an oxide and/or a salt of a metal and/or a non-metal. The BET surface area of the doped oxide may be between 5 and 600 m2/g. The doped pyrogenically prepared oxides of metals and/or non-metals are prepared by adding an aerosol which contains an aqueous solution of a metal and/or non-metal to the gas mixture during the flame hydrolysis of vaporizable compounds of metals and/or non-metals.
Claims18
A process of producing a doped, pyrogenic oxide which is doped using an aerosol, the process comprising:
- providing an aerosol comprised of at least one of a solution and a suspension of a
- doping substance selected from the group consisting of a metal salt, a non-metal salt, a metalloid salt, and a mixture thereof;
- conducting the aerosol through a heating zone by means of a carrier gas stream to thereby evaporate at least a portion of the aerosol;
- mixing the evaporated aerosol in the carrier gas stream with a combustible gas stream which comprises at least one of an evaporated solution and an evaporated suspension of a substance to be doped selected from the group consisting of a metal salt, a non-metal salt, a metalloid salt, and a mixture thereof, to thereby create a combustible gas stream mixture;
- reacting the combustible gas stream mixture in a flame;
- and
- separating the resulting doped, pyrogenic oxide from the reacted gas stream mixture.
A method of modifying aggregate and agglomerate structure of pyrogenic silica doped with cerium salt, comprising:
- providing a precursor of the pyrogenic silica and a precursor of the cerium salt as at least one of a solution and a suspension of the precursors;
- and
- presenting the at least one of a solution and a suspension of the precursors in aerosol form prior to a step of reacting the precursors in a flame.
Dependencies are inferred from the claim text.